Dumbed down consumer electronics: Adding DTV channels

Just curious: Why is it that "modern" TV/VCR/DVD devices only allow auto-scan for DTV channels but no "add some later"? As most of us know DTV is unreliable, meaning sometimes channel 6-1 pixelates out, sometimes 58-2 is gone. So upon setup it will only catch the ones that are currently receivable, which in our case is never more than 80% of digital channels. Changes all the time.

But you can't add, it does a complete new setup, upon which Murphy says it'll miss a few channels it had detected on the previous run. That I find a rather daft technical decision. Is it just me thinking that or is the cleverness in electronics designs really taking a nose-dive?

Sorry for the rant, but I had to let it out.

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Regards, Joerg

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Joerg
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On a sunny day (Sun, 01 Aug 2010 14:14:29 -0700) it happened Joerg wrote in :

I dunno what stuff you use, but here it is very possible to add a frequency or station, or sat. That is both for satellite, terrestrial, both radio, TV, and data. DTV is not 'unreliable', in fact is is very reliable, but it needs a minimal signal strength for things to lock. You should now about PLLs, Viterbi decoding, etc. Did you ever put a decent yagi or some otehr good antenna on the roof?

Reply to
Jan Panteltje

It depends entirely on how ... thoughtful? ... the firmware developers were (or were allowed to be?). One of the converter boxes here (yup, still have old analog CRTs) allows direct entry of the channel + subchannel, either to view or to add. Another permits an "add new channels" scan which only adds but won't delete existing ones if it doesn't see them.

Other features are all over the map, as well. I did spring for a small, modern LCD with ATSC tuner when one of the CRTs went poof. Yeah, it has a super picture but it has an awful channel guide: only the current program name and only for the current channel. And most of the time (like, almost always) the displayed time of day and time of the program are incorrect by hours -- with different offsets for different stations. I'm guessing some programmer forgot his "#pragma packed" or something.

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Rich Webb     Norfolk, VA
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Rich Webb

Mostly the Magnavox brand. Which is AFAIK essentially Philips. But it all seems designed and built by Funai. The lastest box it even says it bluntly in the manual, "add-on" only for analog TV channels. Which no longer exist out here when using terrestrial.

signal

ATSC is unreliable. Ask any neighbor here who uses an antenna.

I do, but it seems the guys who developed and tested ATSC (or shall I say didn't test enough?) may not :-)

Yep, top of the line ChannelMaster. The biggest honking one there is. With mast amp, professional distribution and so on.

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Joerg

I helped set up one LCD-TV that could add on DTV channels. The others didn't :-(

What I am wondering is whether any of this stuff ever gets test-driven in the field. In the areas I work in (med, aero, and similar) that is mandatory and deficiencies like this would hit the fan almost instantly.

The sad thing is, I've even seen similar things happen with "modern" lab equipment. Which is why I often recommend to my clients to shun new stuff and look for a particular boat anchor at liquidations or auctions. They don't make'em like that no more.

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Joerg

On a sunny day (Sun, 01 Aug 2010 14:40:16 -0700) it happened Joerg wrote in :

signal

Sorry to hear that, I did read they improved multipath, maybe not enough.

Politics played some role there I am sure. US had to use their own system. OTOH they say the distances are bigger than in Europe, making 8VSB a better choice. I have no experience with that system, so I dunno if that is reality.

Nice, should really work.

Only thing I can say about it is that I love satellite. With many many free programs here in Europe I guess we are spoiled. I just watched starwars II, I have it on disc also, but it still is a big show. My advice is to use a PC card and or PC as receiver, both for terrestrial and satellite. The quality blew me aways this time, satellite, zero bit errors,. There is a lot of soft for those PC cards that allow you to do many things commercial receivers cannot do, tweak things. Some written by me :-) There is a cute little program in Linux called 'mediainfo'. I just ran it in that starwars recording:

-rw-r--r-- 1 root root 6273528980 2010-08-01 23:20 Astra1_prosieben.20h13.1-8-2010-187m.ts grml: /mnt/hdd4/video/satellite # mediainfo Astra1_prosieben.20h13.1-8-2010-187m.ts General Complete name : Astra1_prosieben.20h13.1-8-2010-187m.ts Format : MPEG-TS Format profile : No PAT/PMT File size : 5.84 GiB Duration : 3h 7mn Overall bit rate : 4 473 Kbps

Video ID : 511 (0x1FF) Format : MPEG Video Format version : Version 2 Format profile : Main@Main Format settings, Matrix : Default Duration : 3h 7mn Bit rate mode : Variable Bit rate : 3 586 Kbps Nominal bit rate : 15.0 Mbps Width : 720 pixels Height : 576 pixels Display aspect ratio : 16/9 Frame rate : 25.000 fps Standard : PAL Colorimetry : 4:2:0 Scan type : Progressive Scan order : Top Field First Bits/(Pixel*Frame) : 0.346 Stream size : 4.68 GiB (80%)

Audio #1 ID : 512 (0x200) Format : MPEG Audio Format version : Version 1 Format profile : Layer 2 Duration : 3h 7mn Bit rate mode : Constant Bit rate : 192 Kbps Channel(s) : 2 channels Sampling rate : 48.0 KHz Resolution : 16 bits Video delay : -407ms Stream size : 257 MiB (4%)

Audio #2 ID : 515 (0x203) Format : AC-3 Format/Info : Audio Coding 3 Duration : 3h 7mn Bit rate mode : Constant Bit rate : 384 Kbps Channel(s) : 2 channels Channel positions : L R Sampling rate : 48.0 KHz Video delay : -377ms Stream size : 514 MiB (9%)

As you see it is much longer than the movie, because of the commercials. Because I view about an hour timeshifted I just fast forward the commercials, or more precisely just jump over those in xine.

The PC as media server is cool,

Reply to
Jan Panteltje

Say Jan,

Since you're doing media encoding on Linux, might I ask: Do you have a favorite MP3 encoder that runs on fixed-point CPUs (...such as ARMs...)?

LAME seems to very much be the defacto standard on floating-point machines, but I've read that it really crawls if there's isn't an actual floating-point ALU around and software emulation is being used.

Thanks,

---Joel

Reply to
Joel Koltner

signal

It ain't good enough for multipath. Analog was better, way better.

choice.

It probably has other reasons as well. For example, people really want hi-def, meaning 1080 interlaced or progressive scan. And I have to say, if the channel doesn't pixelate out on us and a hi-def event like "Dancing with the Stars" airs the picture is truly stunning.

In the US we do not have free satellite :-(

satellite.

Nah. I just wired up this new Magnavox box. Like the one before it has upconversion and all that.

A PC in the living room? Yuck. The most we ever do is connect one to watch photos, a laptop, via a VGA cable tucked behind a cabinet.

commercial receivers

Astra1_prosieben.20h13.1-8-2010-187m.ts

Astra1_prosieben.20h13.1-8-2010-187m.ts

Hmm, we get a lot more resolution than that these days.

Yeah, but you can do the same thing with a DVD recorder. Ok, time shift must be longer than the total play time including commercials. But that is never a problem because we watch one movie in the evening and that's it.

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Joerg

Because not only are the end-users considered to be dumber today, but I suspect a lot of the designers and engineering managers are as well!

There's at least a silver lining that it's generally easier to figure out, e.g., which models *do* still assume you, the user, have at least a half-dozen brain cells still functioning than it would have been 20+ years ago.

---Joel

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Joel Koltner

DTV = "Dumber TV" ?:-) ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Something like that... I'm not sure the total "quality" of TV productoin has risen much over time, whereas the number of channels certainly has, so the "quality" ends off awfully thin on many a channel...

If you want to watch what I consider to at least be chortle-invoking TV, there's at least Penn & Teller's "Bullshit!" on Showtime.

...which I actually don't subscribe to, but I do own the DVDs. Season six (2008, I think --

formatting link
) was quite entertaining... folks who think dolphins are magical critters, the green movement, sensitivity training, etc.

A surprising number of the folks who engage in these, mmm... "alternative lifestyles" seem to prefer to live in your own state, for some reason :-).

Let me know if you'd like to borrow a DVD and I can send it down your way...

---Joel

Reply to
Joel Koltner

Some tuners will let you punch in the real channel in analog mode. For example, I can type "4 5 ENTER" (no dash makes it analog) and it will hop to 44-1. I use the trick to get Sacto stations that won't show up in a scan but are viewable at night.

I wish I could delete obsolete mappings.

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Reply to
Kevin McMurtrie

Better yet, there should be a MANUAL ADD channel option...

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Robert Baer

On a sunny day (Sun, 01 Aug 2010 18:01:01 -0700) it happened Joerg wrote in :

Even PAL, that still gave a picture when it was almost 100% noise, was sufficient perhaps to see what was 'going on', cannot compare in quality to high bitrate DVB-T.

choice.

I do not see the connection between 8VSB and hi-def you are making?

Time to pack up and go Germany again :-)

show.

satellite.

I have a small box for DVB-T (terrestrial), it has an USB connection. ftp://panteltje.com/pub/haupppauge66.gif I even installed a new kernel on the eeePC that can use it, so how big is that? Of course the media centre PC is much bigger, But many modern laptops have a HDMI output, would not be a problem, and you would be able to tweak things in software. Add an other box, a 1TB external harddisk. Does not look so bad.

So do we, the same station is available in HD too, but I think it is encrypted, look for 'ProSieben HD':

formatting link

Now the fun part is, they finally bought HD capable scanners it seems. So now at least the normal 720p is top resolution (it always was low detail). And free. Unless you have 20/20 vision and a real big screen you cannot see the difference anyways :-) So that saves money :-) TV is far more advanced here, Sky will start broadcasting in 3D HD shortly.

TV recording and processing with a PC has way more possibilities.

Reply to
Jan Panteltje

You seem to suffer from frequency selective fading, which is typical in multipath conditions. This may eliminate the signal with sharp notches (usually less than 1 MHz) and these notches are constantly moving around the TV band when the propagation condition changes. Thus, a few channels are suffering from multipath nulls during each channel scan and hence, these are not stored.

The 8VSB modulation used in ATSC is not known for robustness in multipath situations. The help the situation, an equalizer is used at the receiver that tries to compensate for the amplitude and phase errors created by the RF path. The equalizer needs a known training signal so that the equalizer parameters can be set up correctly. There have been claims that with 5th (or was it 6th or 7th :-) generation equalizers, the multipath performance is similar to COFDM DVB-T.

Apparently the 8VSB equalizer can somewhat track the slow RF-channel parameter changes (starting the training session from previously known good parameters), but during the initial channel scan, the equalizer parameters are completely unknown for each new channel, the equalizer is not capable of making any sense of some of the signals, even if the amplitude is quite strong.

My guess is that if you connect a spectrum analyzer to your antenna signal, it will show a comb filter like spectrum.

Diversity receivers are available in DVB-T countries mainly for in-car receivers, but do you have diversity receivers for ATSC ?

Having two antenna towers at slightly different locations (at least some wavelengths from each other) will have a different multipath pattern. When one antenna and receiver drops out, the signal may be good at the other antenna.

Even simple RF summing of two antenna signals at different locations may help avoiding deep nulls.

Reply to
Paul Keinanen

I prefer to be able to see the news even when totally grainy versus what happened yesterday night. About 80% of all digital channels pixelated out, blue screen, and none of the channels with news was left. Time to turn on grandpa's tube radio. Because those work.

It seems the chosen standards over here were squeezed to the limits WRT resolution. And obviously nobody really tested this under multipath.

For a visit, yes. Craving a nice Pilsener from tap, you can't get that in the US. Gordon Biersch brew pubs come close but it still ain't the real thing.

That picture is smaller than a passport photo :-)

How large is that box?

I can't imagine the eeePC to properly display a fast-changing 1080 hi-def image.

Encrypted doesn't do you any good. Our terrestrial HDTV isn't encrypted.

I definitely can see the difference between 720 and 1080. Not that mankind really needs that but looks nice. However, I would prefer NTSC over it any time because that always worked.

Yeah, but what if one doesn't need those? All we want is to record something and watch it later. That's it.

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Joerg

Many engineers as well. Looks like even the design of a simple and functioning POR/BOR is a challenge these days. I never understood what's so complicated about that. Yesterday we had three power outages. After every one of them our "modern" stereo starts to squeal. The DSP in there goes lala and the only way to fix this is cut power again until it stops doing that. Pathetic. Many engineers seem to think that hanging a resistor and a cap to an /RST pin is fine. And many IC designers don't seem to have the foggiest how it's done right.

Oh, and the new VCR still goes 12:00 blinky-blink after each power outage. I have given up hope that they will ever figure out how to do that right. It would be so easy but ...

Some things are, because the manuals are often online. However, you are pretty much stuck with what's available and with a lot of gear the enclosures and names might look different but the innards are the same.

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Regards, Joerg

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Joerg

With most gear that doesn't work because 44-1 could actually be near the old Ch 35 or soemwhere else. Stations gave up their precious VHF channel. HUGE mistake.

Most gear actually lets you do that.

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Joerg

I think they failed to achieve that level of performance. Yesterday _all_ stations that carry evening news blue-screened. Meaning we could not watch the news. I guess this is called progess.

No, it showed nice bricks for each station but the sets can't decode some of them.

Sure, I could build 3-4 towers and provide a remote selector switch in the living room. That would really be technological progress :-)

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Regards, Joerg

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Joerg

I was thinking Amazon reviews and all the "dedicated to electronics" review sites as well; sometimes they get incredibly detailed about what little nuisances a product has and provide some comparisons with other products available. It can even drive product development -- back in the late '90s a lot of motherboards would have their ubiquitous dual-row header connectors just wherever it was easiest for the PCB guy to place them, but it really started improving after the review sites pointed out just how annoying that was for "cable management" and these days it's clearly something all the motherboard manufacturers think about with each new board they release.

But you make a good point that a lot of the same "guts" with a different housing -- and the other trend, where there are, e.g., 50 new TVs released per year, but they're just slight "evolutions" of the previous year's -- doesn't provide as much choice as one might first expect.

--Joel

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Joel Koltner

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